1. Technical Field
The present invention relates to a portable radiographic image capturing device that captures a radiographic image expressed by radiation emission.
2. Related Art
Radiation detectors such as FPDs (Flat Panel Detectors), in which a radiation-sensitive layer is disposed on a TFT (Thin Film Transistor) active matrix substrate and that detect irradiated radiation such as X-rays or the like and output electric signals expressing the radiographic image expressed by the detected radiation, and the like have been put into practice in recent years. As compared with a conventional imaging plate, a radiation detector has the advantages that images can be confirmed immediately, and video images also can be confirmed.
Portable radiographic image capturing devices (hereinafter also called electronic cassettes), that incorporate a radiation detector therein and store radiographic image data outputted from the radiation detector, also are being put into practice. Because the electronic cassette has excellent portability, images of a patient can be captured while the patient lies as is on a stretcher or a bed, and it is also easy to adjust the region to be captured by changing the position of the electronic cassette. Therefore, even situations in which images of a patient who cannot move are to be captured can be dealt with flexibly.
It is generally known that the electrical characteristics of a radiation detector change due to a rise in temperature. Further, heat dissipation and cooling are extremely important in order to improve normal operation and durability of the electric parts.
Thus, in Japanese Patent Application Laid-Open (JP-A) No. 2009-80103, the present applicants disclose a technique in which an electronic cassette is structured by a cassette main body that incorporates a radiation detector therein, and a control unit that is freely detachable from and can be separated from the cassette main body, and that supplies electric power to the radiation detector, and that controls the radiation detector and receives image information. The electronic cassette is structured such that electronic parts that generate heat and the radiation detector can be separated.
Further, JP-A No. 2002-311526 discloses a technique in which a portion of a casing of an electronic cassette can be opened and closed, and a unit part, that includes a radiation detector and that is made into a unit, is structured so as to be removable.
By using the technique disclosed in JP-A No. 2009-80103, the control unit is structured so as to be able to be separated from the cassette main body. By using the technique disclosed in JP-A No. 2002-311526, a portion of the casing of the electronic cassette can be opened and closed, and the unit part is structured so as to be removable. The section that generates heat can thereby be separated from the radiation detector.
However, the techniques disclosed in JP-A No. 2009-80103, and JP-A No. 2002-311526 are not techniques that improve the heat dissipating and cooling efficiency of the electronic cassette itself.
Further, generally, a radiation detector is equipped with an image capturing surface onto which the radiation, that has passed through the subject such as a patient or the like, is irradiated, and the radiographic image that is irradiated onto this image capturing surface is captured. Because the image capturing surface is exposed, it is easily damaged. If the image capturing surface is damaged, it affects the captured radiographic image as well.
In particular, because an electronic cassette can be carried about, it is easy for the radiation surface to be damaged while the electronic cassette is being transported.